Application of Levenberg-Marquardt technique for electrical conducting fluid subjected to variable viscosity

In the present study, design of intelligent numerical computing through backpropagated neural networks (BNNs) is presented for numerical treatment of the fluid mechanics problems governing the dynamics of magnetohydrodynamic fluidic model (MHD-NFM) past a stretching surface embedded in porous medium along with imposed heat source/sink and variable viscosity. The original system model MHD-NFM in terms of PDEs is converted to nonlinear ODEs by introducing the similarity transformations. A reference dataset for BNNs approach is generated with Adams numerical solver for different scenarios of MHD-NFM by variation of parameter of viscosity, parameter of heat source and sink, parameter of permeability, magnetic field parameter, and Prandtl number. To calculate the approximate solution for MHD-NFM for different scenarios, the training, testing, and validation processes are conducted in parallel to adapt neural networks by reducing the mean square error (MSE) function through Levenberg-Marquardt backpropagation. The comparative studies and performance analyses through outcomes of MSE, error histograms, correlation and regression demonstrate the effectiveness of proposed BNNs methodology.

Expectations of healthcare personnel from infection prevention and control services for preparedness of healthcare organisation in view of COVID-19 pandemic

BACKGROUND

During infectious outbreaks like COVID-19, it is essential that every healthcare personnel (HCP) strictly adheres to infection prevention and control (IPC) policies. To boost IPC measures, training to reinforce preventive practices, which are pertinent to needs and encompass the expectations of the HCP, is indispensable. Thus, these expectations of the HCP should be explored.

METHODS

In this cross-sectional descriptive survey, we used convenience sampling technique to ask the participants to list their expectations on of covid-19 IPC training paper based forms. Using the category construction approach, we organised the expectations and grouped the participants on the basis of their work and place of work to analyse the association using the chi-square test.

RESULTS

Many participants expected to learn about the use of PPE and masks, hand hygiene, physical distancing, cleaning and disinfection, basic precautions for personal protection during the training. Expectations also included various administrative queries, sample collection and clinical skills for diagnosis and management. There was significant association of many categories of expectations with the nature and place of work in the hospital.

CONCLUSION

When planning IPC training, these expectations of the HCP may be carefully addressed. Information about causative agent, transmission and clinical aspects may will give a contextual meaning to IPC training. Some important preventive measures, which few participants expected to learn must be analysed in detail to understand the attitude of the HCP towards them. Efforts to appraise the HCP for the importance of these measures and promoting its practice may play a vital role to curb the spread of infectious diseases.

Suprapatellar versus infrapatellar nailing for tibial shaft fractures: A comparison of surgical and clinical outcomes between two approaches

BACKGROUND

Tibial shaft fractures are a relatively common injury and contemporary treatment includes on-axis fixation with a locked intramedullary nail in the majority of cases. The conventional technique is via an infrapatellar approach but currently there is a trend towards the use of a suprapatellar approach. We compared key variables including operative time, radiation exposure and early patient reported outcomes when adopting a suprapatellar approach to tibial nailing in our unit versus our previous experience of infrapatellar tibial nailing.

METHOD

Twenty-eight consecutive patients with tibial fracture underwent tibial nailing via the suprapatellar (SPN) approach. Six patients in the study group were excluded due polytrauma and need for dual orthopaedic and plastic surgery management. We compared outcomes with our most recent 20 consecutive patients who had undergone tibial nailing via an infrapatellar (IPN) approach. Primary surgical outcomes were: operative time, radiation exposure and accuracy of entry point of the nail on both anteroposterior and lateral radiographs. Clinical outcomes included time to weightbearing, time to radiographic union and patient-reported outcome score (Lysholm score).

RESULTS

Forty-eight consecutive patients underwent intramedullary nail fixation for tibial shaft fractures and 42 were eligible for inclusion in our study (22 SPN vs 20 IPN). There were no significant differences in patient demographics or injury patterns between the two groups. Operative time and radiation exposure were significantly lower in the SPN group when compared to the IPN group (115 min vs 139 min ± 12.5) (36 cGY/cm² vs 76.33 cGY/cm² +/- 20.1). Furthermore, patients in the SPN group reported superior outcome scores at a mean follow up of 3 months (8-24 weeks) There were no observed differences in complication rate between groups and time of final clinical follow up at a minimum of 6 months.

CONCLUSION

Our study shows that adoption of the SPN approach requires minimal learning curve, and has the potential benefits of reduced operative time, radiation exposure and superior patient reported outcomes when compared to the conventional infrapatellar approach.

Assessment of the association of heart rate variability and baroreflex sensitivity with depressive symptoms and stress experienced by women in pregnancy

BACKGROUND

Pregnancy is a unique physiological state with systemic changes including cardiovascular, autonomic, hemodynamic and psychological. Increase in incidence of stress and depression in antenatal period has been reported. Autonomic changes in pregnancy and its dysfunction in depression are well documented. However, there is lack of evidence associating cardiovascular autonomic dysfunction to stress and depressed mood in pregnant women.

METHODS

In this correlation study, we assessed cardiovascular autonomic functions of 172 pregnant women using heart rate variability (HRV) and baroreflex sensitivity (BRS). The Edinburg postnatal depression scale (EPDS) was used to evaluate depressive symptoms and perceived stress scale (PSS) was used to assess stress. The HRV and BRS parameters were correlated with EPDS and PSS. Multiple regression analysis was performed for EPDS and PSS individually to study their association with cardiac autonomic functions(CAF).

RESULTS

HRV and BRS were well correlated to EPDS and PSS scores. The depression and stress were found to be significantly associated to autonomic dysfunctions as increased sympathetic and decreased parasympathetic activity. Among various CAF parameters, LF:HF ratio and BRS were found to be significantly associated with depression and stress among these women.

CONCLUSION

LF:HF ratio and BRS may be associated with depression during antenatal period. The depression in antenatal period may add on to cardiovascular risk in expecting mothers.

All cause 30 readmission in patients with history of sudden cardiac arrest

Background

Sudden cardiac arrest (SCA) remains a significant cause of morbidity and mortality. Current evidence on readmission rates and causes after SCA are scarce.

Purpose

To describe patient characteristics, predictors of readmission and outcomes patients with history of sudden cardiac arrest and 30-day readmission

Methods

We analyzed the National Readmission Database for years 2016 and 2017 to identify all patients with initial diagnosis of SCA and 30 days readmission after the initial event. We analyzed baseline characteristics and looked into predictors, outcomes and diagnoses of re-admission.

Results

We identified 79,844 patients with an initial diagnosis of SCA that were discharged alive after index admission. Of those 14,387 (18.01%) had one readmission and 3,978 (4.99%) had more than one readmission. The mean age was 64 years and 41.3% were females. Hypertension, dyslipidemia, diabetes, CAD, CHF and CKD were present in 76.5%, 42.4%, 46.3%, 50.4%, 62.3% and 43.5% respectively. Overall mortality was 9.1% and length of stay 7.8 days. (Table 1). Congestive heart failure was the predominant diagnosis for readmission (Figure). Female sex (HR=0.93; p=0.004) was the only independent risk factor for all cause readmission.

Conclusions

Patients with history of SCA that have a 30-day readmission have significantly more comorbidities and length of day. Congestive heart failure is the predominant diagnosis for readmission

Funding Acknowledgement

Type of funding source: None

Prevalence of vitamin K deficiency in older people with hip fracture

Introduction: Vitamin K plays an important role in blood coagulation. Diet is the main source of vitamin K and body stores are depleted in days, hence deficiency is common in malnourished older people. A high proportion of people who sustain a hip fracture are already malnourished, compounded by fasting for surgery which might further increase deficiency. We wanted to explore the prevalence of vitamin K deficiency in hip fracture patients and the impact of a short period of fasting.Methods: In consecutive patients hospitalised with a hip fracture, we measured vitamin K and PIVKA-II (undercarboxylated factor II - a marker of subclinical vitamin K status) on admission and on first post-operative day. We excluded those on anticoagulants.Results: N = 62 participated; 4 had missing pre-op vitamin K samples and n = 3 had no surgery leaving n = 55 with paired samples. Mean age was 80.0 ± 9.6 years, 33% males. Prevalence of subclinical vitamin K deficiency on admission was 36% (20/55) based on reference range of > 0.15µg/L. The proportion with subclinical K deficiency after surgery rose to 64% (35/55), p < 0.05. 13% had detectable PIVKA-II concentrations pre-operatively, 15% did post-operatively. None had abnormal prothrombin time. Vitamin K status was not associated with post-operative haemoglobin drop or transfusion requirements.Conclusion: Prevalence of vitamin K deficiency in hip fracture patients is high and increases further following a short period of fasting. Though no significant impact was noted on peri-operative blood loss, larger studies are warranted to explore this, and the potential role of vitamin K supplements peri-operatively.

P4171Population characteristics, interventions and outcomes in hospitalized orthotopic heart transplant patients with sudden cardiac arrest: a nationwide United States analysis from 2007 to 2015

Background

Sudden cardiac arrest (SCA) is a leading cause of death in the United States (US), claiming up to 450,000 lives annually and accounting for ∼25% of deaths following orthotopic heart transplantation (OHT),

Purpose

We sought to characterize OHT patients suffering SCA and their subsequent management, in comparison to the general, native heart (NH) population, using a large national inpatient database.

Methods

A cross-sectional analysis was performed among US OHT & NH patients hospitalized with incident SCA or ventricular fibrillation/flutter. We analyzed demographics, baseline characteristics, procedural utilization and outcomes. Groups were compared with standard statistical techniques. A P-value <0.05 was considered significant.

Results

From 2007–2015, 920 SCA admissions were identified among 121,083 (0.8%) OHT hospitalizations, compared to 1,731,658 (0.6%) in the general population (P<0.001). OHT patients were younger (P<0.001) and predominantly men (P<0.001). More OHT patients had diabetes (P=0.01), while the NH group had more coronary disease (P=0.01). Mechanical circulatory support use was similar in both groups overall, and OHT patients were more likely to undergo transplantation (P=0.015). Pacemaker/defibrillator implants were more common in NH than OHT patients (P<0.001). Acute kidney injury and in-hospital mortality were significantly greater in OHT patients.

Table 1. SCA in OHT & general populations Orthotopic Heart Transplant General Population P-value (N=121,083) (N=278,463,550) Sudden cardiac arrest (SCA) events, n (%) 920 (0.8%) 1,731,658 (0.6%) <0.001 Age, mean (SD) 57 (17) 66 (16) <0.001 Male sex, n (%) 644 (72%) 1,004,362 (58%) <0.001 Coronary artery disease, n (%) 275 (30%) 675,908 (39%) 0.012 Mechanical circulatory support, n (%) 64 (7%) 104,151 (6%) 0.230 Repeat heart transplantation, n (%) 5 (0.5%) 1199 (0.1%) 0.015 Pacemaker or defibrillator implant, n (%) 45 (5%) 136,314 (8%) <0.001 In-hospital mortality, n (%) 555 (60%) 932,812 (54%) 0.014 Cardiogenic shock, n (%) 78 (8%) 208,778 (12%) <0.001 Acute kidney injury, n (%) 418 (45%) 608,035 (35%) 0.003

Conclusions

SCA hospitalizations occur more often and with higher mortality in OHT patients compared to the general population. Earlier recognition of at-risk patients may result in improved utilization of potentially life-saving therapies.

Additive manufacturing: current concepts, future trends

Increasing innovation in rapid prototyping (RP) and additive manufacturing (AM), also known as 3D printing, is bringing about major changes in translational surgical research. This review describes the current position in the use of additive manufacturing in orthopaedic surgery. Cite this article: Bone Joint J 2018;100-B:455-60.

Patients that benefit from buprenorphine-naloxone on medically assisted treatment for opioid dependence in Malaysia

INTRODUCTION

Opioid dependence is recorded as the most common drug of abuse in Malaysia. Currently, the preferred substitution therapy for most Government treatment centres is methadone used as substitution therapy for opioid dependence. There are, however patients who may benefit from being on the combined buprenorphine-naloxone formulation as substitution therapy instead. We discuss six cases of opioid dependence of varied backgrounds that were treated with buprenorphinenaloxone therapy and their outcomes.

DISCUSSION

All of the reported patients improved after the induction of buprenorphine- naloxone. Two of the cases highlighted the transfer of patients on methadone to buprenorphine-naloxone due to the adverse effect and interactions of methadone with other medications. During the transfer there were no major adverse reactions noted, and patients were safely able to continue with the maintenance therapy of buprenorphine- naloxone.

CONCLUSION

Buprenorphine-naloxone is a safe and effective drug substitution therapy for opioid dependence. It has fewer interactions with other medications, and has similar efficacy to methadone. Being a partial agonist, it has a less sedating effect making patients more functional.

Production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) depolymerase from Aspergillus sp. NA-25

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) degrading thermophilic fungus was isolated from soil sample collected from waste disposal site, Islamabad, Pakistan. It was able to grow efficiently on a medium containing PHBV as a sole source of carbon and has been identified as Aspergillus sp. NA-25 by 18S rRNA. Using 9% of inoculum maximum production of PHBV depolymerase was observed at 45 degrees C, pH 7.0 in the presence of 0.2% lactose as an additional carbon source. PHBV depolymerase was purified by precipitation with 80% ammonium sulfate and gel filtration chromatography on Sephadex G-75. The four enzyme forms obtained after gel filtration were analyzed on SDS-PAGE and their molecular weights (36, 68, 72 and 90 kDa) were determined. They were characterized on the basis of effect of different temperatures, pH, metal ions and different reagents on the PHBV activity and stability. It is obvious that the fungal strain Aspergillus sp. NA-25 is capable of degrading PHBV with the help of different types of depolymerases.

Degradation of polyisoprene rubber by newly isolated Bacillus sp. AF-666 from soil

Various microorganisms were screened for their ability to degrade polyisoprene rubber (natural rubber latex gloves). Strain AF-666, newly isolated from a soil sample, was selected as the best strain having the ability to grow on polyisoprene containing plates. The strain identified as Bacillus sp. AF-666, was found to degrade polyisoprene rubber, both on basal agar plates (latex overlay) as well as in liquid medium. Qualitative analysis of degradation was done through scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy SEM showed changes in surface morphology, like appearance of pits and cracks, and marked difference in transmittance spectra of test and control due to changes in the functional groups, was detected through FTIR. CO2 evolution as a result of rubber degradation, was calculated gravimetrically by Sturm Test. About 4.43 g/1 of CO2 was produced in case of test, whereas, 1.57 g/1 in case of control. The viable number of cells (CFU/ml) was also higher in test than in control. Present study may provide an opportunity for further studies on the applications of biotechnological processes as a tool for rubber waste management.

Day case total joint arthroplasty in the hand: results in a district general hospital

The aim of this study was to review the short-term results of joint replacement in the hand, comparing those done as day cases with those done as inpatients. Procedures included trapeziometacarpal, metacarpophalangeal and proximal interphalangeal joint arthroplasties. For day cases a portable laminar flow machine was used, whereas inpatient procedures were carried out in a laminar flow theatre. The postoperative regime was the same in the two groups. The mean follow-up was 12 months. There was no difference in complications, revisions, pain scores and Quick-DASH scores. No early loosening has been detected in any patients at a minimum of 12 months' follow-up. All patients who had day surgery were satisfied with the care. The results of day case small joint arthroplasty of the hand are similar to those in inpatients.

Analysis of cover of the femoral head in normal and dysplastic hips: new CT-based technique

We present a new CT-based method which measures cover of the femoral head in both normal and dysplastic hips and allows assessment of acetabular inclination and anteversion. A clear topographical image of the head with its covered area is generated. We studied 36 normal and 39 dysplastic hips. In the normal hips the mean cover was 73% (66% to 81%), whereas in the dysplastic group it was 51% (38% to 64%). The significant advantage of this technique is that it allows the measurements to be standardised with reference to a specific anatomical plane. When this is applied to assessing cover in surgery for dysplasia of the hip it gives a clearer understanding of where the corrected hip stands in relation to normal and allows accurate assessment of inclination and anteversion.

Effect of foliar application of micronutrients on the yield and quality of sweet orange (Citrus Sinensis L.)

An experiment was designed to study the effect of foliar application of micronutrients on the yield, quality and leaf composition of sweet orange, Blood red variety at Shabazgari, Mardan. The experiment was laid out in a randomized complete block design in 2) factorial arrangement. Zinc, manganese and boron were applied as foliar spray at the rate of 0.4, 0.2 and 0.04 kg ha(-1), respectively in the presence of 1.56 kg N ha(-1) as urea and 0.4 kg surfactance ha(-1) (as wetting agent) in 400 L of water. The maximum fruit yield was obtained, when 0.4 kg Zn ha(-1) and 0.2 kg Mn ha(-1) was sprayed along with 1.56 kg N ha(-1) and 0.4 kg surfactance ha(-1) in 400 L of water. The minimum % peel was obtained with B alone and minimum % rag with Zn + Mn, maximum fruit size with Zn + B and maximum fruit volume with Zn + Mn. Similarly, % juice in sweet oranges was increased significantly by B alone, reducing sugar by Mn alone and vitamin C contents by Zn + B through foliar spray, suggested that each micronutrient had different role on the quality of citrus fruit. Foliar spray of Zn, Mn and B along with urea significantly increased the concentration of Zn and Mn in citrus leaves, while the concentration of B was not affected with foliar spray, perhaps due to dilution within the citrus tissues. Therefore, it is suggested that either Zn+Mn or Zn+B may be applied as foliar spray in combination with urea and surfactance for getting the maximum yield and improved quality of citrus fruit under prevailing conditions.

Prescription and dispensing practices in public sector health facilities in Pakistan: survey report

OBJECTIVES

To gather information on existing prescription practices, dispensing practices and patient satisfaction in government health services of the NWFP, Baluchistan and Punjab province.

METHODS

A cross sectional study design was used for this purpose. Ten health care facilities were selected from each province keeping appropriate representation from first level health facilities, district health facilities and tertiary care hospital. Analysis of selected indicators was carried out on the basis of provinces, health facilities, gender and different age groups.

RESULTS

Documentation of 914 responses was completed from three provinces. Almost equal distribution of encounters was maintained representing different health facilities. Forty seven percent of encounters involved children under 15 years of age. Female patients comprised of 56% and the mean age of the entire sample was 26 years. The mean dispensing time was only 38 seconds, the mean consultation time was 1.79 minutes and the average number of drugs per prescription turned out to be 2.7 out of which only 1.6 drugs were being dispensed from the facility. More than half of the prescriptions contained antibiotics and 15% of patients were prescribed with injectables. Only half of the patients expressed satisfaction with their visit to health facility.

CONCLUSIONS

Like many other developing countries, prescription and dispensing practices are not satisfactory in public sector health facilities of Pakistan. Appropriate and workable solutions need to be developed and implemented in the country to improve systems. Regular audits and qualitative studies should become part of the effort.

Hyperlucent thorax from rotation. Anatomic basis

RATIONALE AND OBJECTIVES

The authors studied a large group of patients with a computed tomography (CT)-based model to evaluate the presence, significance, and anatomic basis of unilateral hyperlucency from patient rotation.

METHODS

Chest CT sections at three levels in 65 consecutive patients undergoing routine diagnostic studies were read into a microcomputer. Radiographic transmittance data were calculated across each CT section at different degrees of rotation as well as for lateral decentering. Data were analyzed for the pattern of density variation both individually as well as in stratified subgroups.

RESULTS

The data showed a trend of increasing radiographic transmission on the side opposite that of the anterior obliquity. The resulting optical density difference was small and was not clinically significant. Lateral decentering produced smaller changes than rotation. The anterior breast/pectoral structures are the etiology for the phenomenon. Optical density differences of 0.1 result from a difference in tissue thickness of 4 mm.

CONCLUSIONS

The changes in radiographic transmission with rotation are small and are overshadowed by soft tissue compression. Rotation alone will result in decreased radiographic transmission on the side of anterior obliquity; thus, the left side will be more lucent in an right anterior oblique projection.

Value of increasing film processing time to reduce radiation dose during mammography

We systematically tested the effects on radiation dose and image quality of increasing the mammographic film processing time from the standard 90 sec to 3 min. Hurter and Driffield curves were obtained for a Kodak Min-R-OM1-SO177 screen-film combination processed with Kodak chemistry. Image contrast and radiation dose were measured for two tissue-equivalent breast phantoms. We also compared sequential pairs of mammograms, one processed at 90 sec and one at 3 min, from 44 patients on the basis of nine categories of image quality. Increased processing time reduced breast radiation dose by 30%, increased contrast by 11%, and produced slight overall gains in image quality. Simple modifications can convert a 90-sec processor to a 3-min unit. We recommend that implementation of extended processing be considered, especially by those centers that obtain a large number of screening mammograms. Three-minute film processing can reduce breast radiation dose by 30% and increase contrast by 11% without compromising image quality.

Bilateral multiple ureteral diverticula diagnosed after ileal loop procedure: report of a case and review of the literature

We report a case of multiple diverticula of the ureter. The clinical and radiological findings of the previously reported 41 cases, including our own, are analyzed, and the microscopic findings of the condition are reviewed. Multiple diverticula of the ureter or ureteral diverticulosis is most likely an acquired condition with a distinct radiological appearance.

Does infection play a role in breast capsular contracture?

The formation of capsular contracture around silicone implants continues to be the most common complication of augmentation mammaplasty. To date, the etiologic factors in the formation of capsular contractures have remained inconclusive. In the present study, the role of subclinical infection with S. epidermidis as a cause of capsular contracture was evaluated in 16 rabbits using miniature silicone implants. All the implants on the side contaminated with varying concentrations of S. epidermidis developed breast capsular contractures. Using Baker's classification, they were graded III or IV, while the controls were all considered to be either grade I or II. Grossly, the capsules on the contaminated side were firm, fibrous, and 2 to 3 times thicker than the controls, and this was confirmed histologically using micrometry. Implants contaminated with 10(7) bacteria uniformly extruded. The present study seems to indicate that subclinical infection with Staphylococcus epidermidis may be one of the causes of capsular contracture around breast implants.